Effects of Brazelton demonstrations on later parenting: a meta-analysis.

Meta-analysis of parenting interventions based on the Neonatal Behavioral Assessment Scale (NBAS) was conducted. Only published studies (n = 13) were included in this analysis, with one effect size entered for each study. The studies contained a total of 668 families, an average of about 51 per study. Effect sizes are reported in terms of the correlation coefficient (r) as well as the difference between experimental and control group means divided by the pooled standard deviation (Cohen's d). Analyses were conducted by weighting each study equally (unit weighting) and also by sample size. Similar average effect size were obtained for both weighting procedures (r's of about.2, d's of about.4), indicating that Brazelton-based interventions during the neonatal period have a small-moderate beneficial effect on the quality of later parenting. The probability of obtaining these findings by chance approached zero. The potential factors influencing these results are discussed, as well as directions for future research.